Wood-pulp grinder



H. E. TlDMARSH.

WOOD PULP GRlNDER.

APPLICATION FILED' FEB. 28, 1921.

Patented Jan. 31, 1922.

vwmboz M. 6 W OW w w W m h M -.-'-Be it known-that I, HARRY residing at Ban or, in the county of Penob-' UNITED T ES ATENT "HARRYELMER; TIDMARSH, or BANGOR, MAINE, ASSIGNOR r UNION'IRON Worms,

7 or BANGOR, MAINE, A CORPORATION OFIVIAINE. a

wow-PULP GRINDER.

T 0 all whom it may concern: V a

E. TIDMARS-I-I,

soot, State of l aine, haveinvented certain new and useful Improvementsin WVood-Pulp Grinders; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable Others skilled in the art to which it appertainsto make and use the same. I

- --Th1S invention relates to wood-pulp grind- 1 ers, and more particularly to the pockets used 1n multi-pocket grinders.

,21 One ofthe common forms of mechanical wood-pulp; gr1nders -c0mpr1ses a series of j radial pockets disposed about the. upper half of the grindstone periphery,.int'o which the wood to be groundis placed and forced Qagain st the .rapidlyrotating (stone. .,,The

ground wood is washedfloutwardly between the foot of the pocket andthe stone or I c. y D

. 2 supported 1n.bear1ngs 3 and rotating wlthi.through slots in thebaseof the pocket Walls wandispcarried away to the screens. It is a Qoommon "defect of such grinders, however,. that part of thewood ground in one pocket is carried around by the stoneito succeeding. pockets ..and, reground. jTheseusuccessive v fgrindingsfiresult in the production of socalled wood-flour in whichthe ,fibreslhave been groundsio fine thattheylcannot be used in paper malnng. ,Such' flour musttherjefore be separated fromthe restof the pulp It is clear then,;, that when the ,ground .woodjis carried from pocket topocket there is a needinferior non-uniform pulp results.

less waste of both energy: and materialand an 3 A device for avoiding this. difficulty is shown and described in my U. S. l Patent No.

.. l,231',67-1', .Jul'y3, 1917 andconsists of a V-.

, .4Q shaped;defleotonor plow held adjacent the devise other'means for forcing the face iof the'ggrindstonesufch mea s being cap b le in epe nt- 1 e it ei y temp eyt i n ce i is i w h he. P w jscraper describedabove, l

' war dly tlilslbts the baseof'thetralnsversel 1 :qfit erq kets P p se m ii ein i Specification 6f Letters Patent. P t ted Application filed February 28,-1921. Serial No. 448,490.

through these slots isthus given an: initial lateral thrust which tends to carry-it over the :edges ofthe, stone, and when deflectors such as those described above are also employed the pulp is carried over to the edges of the stone-with a minimum of effort.

In order that theinven'tion may be more clearly understood, reiterenceis had to the accompanying drawing. disclosing a preferred embodiment thereof, and yinwhioh Fig. 1 is an elevation of a four pocket, wood pulp grinder; Fig. 2is an elevation, ,otone of the pookets'of the grinder SlIOWIIlIl Fig. 1

Fig. 3 is a vertical section through oneof these pockets taken on line 3- 3 of 1 and Fig.4 is a planet one of the pockets looking upwardly/and showing one of the Vv-shaped deflecting scrapers positioned relative to the pocket. s i 4, i rinder. :thus illustrated comprises a,

rotary grindstone' -1; mounted upon a shaft ahousinge, uponwhich are adjustably mounted four radial pockets 55., Each of these pockets is provided ithLtheusual hydraulic-cylinder 6. in whichthe pistoli moves which actuates the pressure foot" commonly employed inforcing the Wood in the pocket against the'rotating stone. The pockets 5 are adjustably mounted' upon :supporting members 7 through bolts 8 ,1which are secured to the pockets through lugs 49. ,The pockets are fixed'to 'thehousing lfin theirjadjusted position means of bolts 10,' which pass through the walls of the housing and .slots 12 in depending apronslli-l,which fare invte al W th t p ck The grinder shown is also providedwith deflecting scrapers '14, which are adjustably "supported upon therear sides of three of the pockets. It is obviously unnecessary't'o provide the last pocket with any scrapingmeans. Each scraper is provided with two rodsflo, which pass through outstanding lugs 16 on the rear face of each pocket and each scraper is adjustably secured to'its pocket by means ot'suitable nuts. The "foregoing arrangement, is such that the. scrapersjarebo'dily adjustablew'ith the pockets fand likewis'e separately adjustable with reference tofthe pocketsthemselvesn" "*Eac'h pocket "isprovided wlth slots I? in the baseof its walls and itis' through these f'slots that theground wood escapes. The

slots i'nthe transverse"walk ngofthgipoclrets n are angularly disposed and are directed outwardly. Each transverse Wallis provided with two seriesof slots which diverge outwardly as most clearly shown in Fig. 4. Diverging slots have been shown in both of-the transverse walls of the pocket. It is clear, however, that theslots in only one wall, and that the rear wall, are in use at any given time. The slots in the forward wall serve no purpose. On the other hand, they are not detrimental and each pocket iscastwithslots in both transverse walls, so that it may be employed on either a right or left hand grinder.

The operation of the grinder is as follows:

Wood is fed intothe several pockets and continuously forced against the grindstone Which rotates in the direction-indicated by the arrow. As the wood is ground some of it is washed outwardly through the slots 17 in the end walls of the pockets. This wood falls into the space between the housing and the stone andis eliminated. The rest-of the pulp passes forwardly in the direction of movement of the stone through diverging slots 17. When it has passed from the pocket it impinges upon deflecting scraper 14 and is forced outwardly toward'the edges of the grindstone and thus removed. The pulp in passing "through the outwardly diverging slots is given an initial impetus which tends to forceit over theedges oft-he stone. When the pulp having this lateral movement strikes against the scraperl l it is easily deflected and forced over the side of 'thestone. Both scraper and pocket'bei'ng adjusted 'to lie as close to the face of the stone as possible, it is practically impossible for any of the pulp [to pass out of a pocket except through the slots, and also practically impossiblefor it to pass beneath a's'cra'per and be carried into the adjoining pocket. In this way regrinding is eliminated and the efiicienc'y of the machine increased according-1y.

Although the use of diverging slots has been shown and described and in-connection with a V-shaped plow or scraper, it is clear that for a narrower stone it might be feasible to -employ only-oneseries ofslots, all being parallel, but directed outwardly and used in conjunction with a plane, angular-1y disposed, deflector.

one of its walls.

3. A pocket for wood-pulp grinders havang outwardly zdiverging slots in the base -.of-:its reai transverse wall.

4. A wood-pulp grinder comprising aroytary; grindstone, rapocketpositioned radially thereof, an angularly disposed scraper be:

passing to the nextpocket and'beirigreground, each of said scrapers belngfmounted slots in the base of the pocket wall adjacent the scraper. i

5. A wood-pulp grinder comprising a rotary grindstone, a series of radially disposed pockets about said grindstone, angularly disposed scrapers behind certainof the pockets and outwardly directed slots in the base of the pocket walls adjacent the scrapers.

6. A wood-pulp grinder comprising ajrotary grindstone, a series of radially disposed pockets about said grindstone, V-shaped deflecting scrapers behind certain of the pockets' and outwardly diverging slots injthe base of the pocket walls adjacent the scrapers. V

7. A grinder for the production of"wo0'd pulp comprising a rotary, grindstone, a p'lu rality of pockets arranged around thestone' for receivingfthe' wood to "be ground and provided with means for feeding' the'wood against the stone, and'scrapersa'rranged be. tween the pockets and adjustable therewith with respect to the stone, said scrapers being arranged to remove the pulp produced and thereby prevent the same from passing to the next pocket and being regroundfthe base of each pocket'wall adjacent a se ra'p'er being provided with outwardly fdi-rected slots. V

8. A grinder for the production of wood pulp comprising "a rotary'grindstone ,fa pluhind said pocket and outwardly directed i rality of pocketsarranged around thestone for receiving the wooditobe groundfand provided with means for feeding'the'wvood against'the stone, andscra'p'ers arranged between the pockets and. adjustable with. re-

ioo

spect to both the pockets andthe*sto-ne ,said

scrapers being arranged to removethe pulp produced and thereby prevent the samefrom passing to the next pocket iand being freground, the base of'eac'h pocket wall ad jacent a scraper being providedwith outwardly directed slots. p I v I i i 9. Agrinder for ithe production of wood pulp comprising a'rotarygrindstone, a plue rality of pocketsv arranged around 'thestone for receiving the woodto be groundand provid ed with means for feeding the wood against the stone, and scrapers arrangedg be tween the pocketsfor removing the pulpproduced and thereby preventing the same from upon one of the pockets and being adjustable with respect thereto,the baseflo'feach pocket wall .adjacenta scraper "being' prm ,ceiving the woodto "be groundaand hayingv means for feeding the Wood against the llsd stone, and scrapers arranged between the pockets and adjustable with respect to both the pockets and the stone, the adjusting means being outside of the casing, said scrapers being arranged to remove the pulp produced and thereby prevent the same from passing to the next pocket and being reground, the base of each pocket wall adjacent a scraper being provided with outwardly diverging slots.

11. A grinder for the production of wood pulp comprising a rotary indstone, a casing therefor provided wit a plurality of pockets arranged around the'stone for receiving the wood to be ground and having 15 means for feeding the wood against the stone, and scrapers arranged between the pockets for removing the pulp producedand thereby preventing the same from passing to the next pocket and being reground, each 20 of said scrapers beingmounted upon one of the pockets and being adjustable with respect thereto, and adjusting means being located Without the casing, the base of each pocket wall adjacent a scraper being pro- 25 vided with outwardly diverging slots.

In testimony whereof I aflix my si nature.

HARRY ELMER TIDMA SH.

Certificate of Correction.

It is hereby certified that Letters Patent No. 1,405,356, granted January 31,

1922, upon the application of Harry Elmer Tidmarsh, of Bangor, Maine, for an improvement in Wood-Pulp Grinders, Were erroneously issued to Union Iron Works, of Bangor, Maine, a Corporation of Maine, as assignee of the entire interest in said invention, Whereas said Letters Patent should have issued to the inventor, said Tid'marsh and Union Iron Works, of Bangor, Maine, said corporation being assignee of one-half interest only in said invention, as shown by the record of assignments in this oflice; and that the said Letters Patent should be read With this correction therein that the same may conform to the record of the case in the Patent Office. 7

Signed and sealed this 7th day of March, D., 1922.

[sEAL.] WM. A. KINNAN,

Acting Commissioner of Patents. 

